Synthetic iron Chelates to correct iron deficiency in plants

Abstract

This article reviews the effectiveness of synthetic Fe-chelates to correct Fe chlorosis. Soil application of such compounds is usually a more efficient strategy to overcome Fe chlorosis of crops grown on calcareous soils as compared with treatments based on inorganic Fe salts or weak Fe-complexes. To understand the effectiveness of Fe-chelates, it is necessary to have knowledge on their stability, their chemical equilibria in soils and other factors that may affect their presence in soil solution. Sorption into soil surfaces should be also considered as a factor affecting Fe availability. Strategy I plants may obtain Fe even from the most stable chelates, but, among them, plants can take up Fe better from the less stable ones. Also, both the stereochemistry and the net charge of the Fe-chelates are important factors affecting their uptake by the plant. There is a wide variety in quality among commercial chelates, so that the use of reliable analytical methods is necessary to assess their purity and predict their behavior in field conditions. © 2006 Springer.